Nickel-based alloy

Abstract: A nickel-based alloy which is excellent not only in anti-corrosion properties but also in workability is disclosed. The alloy contains 15 to 35 weight % of chromium; 6 to 24 weight % of molybdenum; wherein the sum of chromium plus molybdenum is no greater than 43 weight %; 1.1 to 8 weight % of tantalum; and balance nickel and unavoidable impurities. The alloy may optionally include no greater than 0.1 weight % of nitrogen; no greater than 0.3 weight % of magnesium, no greater than 3 weight % of manganese, no greater than 0.3 weight % of silicon, no greater than 0.1 weight % of carbon, no greater than 6 weight % of iron, no greater than 0.1 weight % of zirconium, no greater than 0.01 weight % of calcium, no greater than 1 weight % of niobium, no greater than 4 weight % of tungsten, no greater than 4 weight % of copper, no greater than 0.8 weight % of titanium, no greater than 0.8 weight % of aluminum, no greater than 5 weight % of cobalt, no greater than 0.5 weight % of vanadium, no greater than 2 weight % of hafnium, no greater than 3 weight % of rhenium, no greater than 1 weight % of osmium, no greater than 1 weight % of platinum, no greater than 1 weight % of ruthenium, no greater than 1 weight % of palladium, no greater than 0.1 weight % of lanthanum, no greater than 0.1 weight % of cerium, or no greater than 0.1 weight % of yttrium.

Description: BACKGROUND OF THE INVENTION Field of the Invention This invention relates to a Ni-based alloy which is excellent in anti-corrosion properties, in particular anti-pitting corrosion property and anti-crevice corrosion property in an environment containing chlorine ions, as well as in workability, in particular workability in hot working. Conventional Art Ni-based alloys having excellent anti-corrosion properties have hitherto been used in the manufacture of exhaust gas desulfurizers for chemical plants, electroplating devices, boilers or the like; structural members for semiconductor devices; food processing devices; medical equipment; and various cutter blades and manual tools which are exposed to sea water; or the like. Ni-based alloys conventionally known as such anti-corrosive alloys include a Ni-based alloy (hereinafter referred to as "alloy 55C") disclosed in Japanese Patent Application, Laid-Open (First-Publication) No. 62-40337, and consisting of 30.1 weight % of Cr, 20.3 weight % of Mo, balance Ni and unavoidable impurities; a Ni-based alloy (hereinafter referred to as "alloy 625") disclosed in United States Patent No. 3,160,500 and consisting of 21.5 weight % of Cr, 9 weight % of Mo, 2.5 weight % of Fe, 3.7 weight % of Nb, balance Ni and unavoidable impurities; a Ni-based alloy (hereinafter referred to as "alloy C-276") disclosed in United States Patent No. 3,203,792 and consisting of 16.1 weight % of Cr, 16.2 weight % of Mo, 5.2 weight % of Fe, 3.2 weight % of W, balance Ni and unavoidable impurities; and a Ni-based alloy (hereinafter referred to as "alloy C-22") disclosed in United States Patent No. 4,533,414 and consisting of 21.5 weight % of Cr, 13.2 weight % of Mo, 4.1 weight % of Fe, 3.1 weight % of W, balance Ni and unavoidable impurities. FR-A-2 049 528 describes an alloy composed essentially of 14.7-18 wt.% chrome, 3.5-9.0 wt.% tantalum, 15-18 wt.% molybdenum, 0.02-0.15 wt.% carbon, 0.3-1.5 wt.% silicon, 0.3-1.5 wt.% manganese and optionally tungsten, iron, vanadium, cobalt, copper, niobium and nickel. GB-A-2 102 834 relates to an alloy for making a high strength deep well casing and tubing having improved resistance to stress-corrosion cracking. The composition is characterized by 30-60% Ni, 15-35% Cr, 0-12% Mo, 0-24% V, further N, Cu, Co, rare earth metals, Y, Mg and Ca as optional components. The content of P is to be limited to less than 0.030% and S to less than 0.005%. One or more of Nb, Ti, Ta, Cr and V may be present in the total amount of 0.5-4.0%. DE-A-25 197 44 describes an alloy for dental applications, characterized by the main components Ni (60-70 wt.%), Cr. (18-23 wt.%), Mo (5-10 wt.%) and Nb + Ta (traces to 4 wt.%). The alloy may further contain Fe, Si, Mn, Ti, Al and C. JP-A-63 053 233 describes a nickel-based alloy comprising at least 50% Ni, 20-25% Cr, 7-12% Mo, 2.5-5.5% in total Nb and Ta, and besides C, Mn, Fe, Al, and Ti as minor components, up to 0.015% S. Optionally, Y, Mg and Ca are employed in an amount up to 0.01%. However, the demands for the anti-corrosive Ni-based alloys having more excellent anti-corrosion properties and workability have been increasing because anti-corrosive Ni alloys are being utilized in progressively severe environments in recent years, and because the devices employed in such environments have come to have more complicated shapes. The aforesaid conventional Ni-based alloys are therefore not satisfactory. More specifically, "alloy 625", "alloy C-276" and "alloy C-22" exhibit excellent workability in hot working, but are inferior in anti-corrosion properties, in particular anti-pitting corrosion property and anti-crevice corrosion property in an environment containing chlorine ions. In contrast, "alloy 55C" exhibits excellent anti-corrosion properties in the environment containing chlorine ions, but is inferior in workability in hot working operation. SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to provide a Ni-based alloy which is excellent not only in anti-corrosion properties but also in workability. Another object of the invention is to provide a Ni-based alloy which exhibits superior corrosion resistance in particular in the environment in which chlorine ions are contained. Yet another object of the invention is to provide a Ni-based alloy which is resistant to acids such as hydrochloric acid, hydrofluoric acid, oxalic acid, phosphoric acid, or nitric acid; alkalis such as sodium hydroxide; and sea water which is neutral. A further object of the invention is to provide a Ni-based alloy which is particularly resistant to a variety of sulfuric acid corrosion. According to the present invention, there is provided a Ni-based alloy consisting of: 15 to 35 weight % of chromium; 17 to 23 weight % of molybdenum; wherein the sum of chromium plus molybdenum is no greater than 43 weight %; 1,3 to 3,4 weight % of tantalum; optionally, no greater than 0.1 weight % of nitrogen; no greater than 0.3 weight % of magnesium, no greater than 3 weight % of manganese, no greater than 0.3 weight % of silicon, no greater than 0.1 weight % of carbon, no greater than 6 weight % of iron, no greater than 0.1 weight % of boron, no greater than 0.1 weight % of zirconium, no greater than 0.01 weight % of calcium, no greater than 1 weight % of niobium, no greater than 4 weight % of tungsten, no greater than 4 weight % of copper, no greater than 0.8 weight % of titanium, no greater than 0.8 weight % of aluminum, no greater than 5 weight % of cobalt, no greater than 0.5 weight % of vanadium, no greater than 2 weight % of hafnium, no greater than 3 weight % of rhenium, no greater than 1 weight % of osmium, no greater than 1 weight % of platinum, no greater than 1 weight % of ruthenium, no greater than 1 weight % of palladium, no greater than 0.1 weight % of lanthanum, no greater than 0.1 weight % of cerium, and no greater than 0.1 weight % of yttrium; and balance nickel and unavoidable impurities. With the above composition, the Ni-based alloy of the invention comes to have not only sufficient anti-corrosion properties but also excellent workability in the hot working. In particular, the Ni-based alloy of the invention is the most useful when used in an environment containing chlorine ions, and is also sufficiently resistant to acids such as hydrochloric acid, hydrofluoric acid, oxalic acid, phosphoric acid, or nitric acid; alkalis such as sodium hydroxide; and sea water which is neutral. The Ni-based alloy of the invention may further be modified so as to include 17 to 22 weight % of chromium; 19 to 23 weight % of molybdenum; wherein the sum of chromium plus molybdenum is greater than 38 weight % and no greater than 43 wt.%; 1.3 to 3.4 weight % of tantalum; 0.01 to 4 weight % of iron; and optionally no greater than 0.01 weight % of zirconium, no greater than 0.01 weight % of boron, no greater than 0.5 weight % of niobium, no greater than 2 weight % of tungsten and no greater than 2 weight % of copper, wherein [4 x niobium + tungsten + copper ] ≤ 2 weight %. With this modification, the resulting Ni-based alloy comes to have excellent resistance to a variety of sulfuric acidic corrosive environments. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view showing a test piece used in a crevice corrosion test. DETAILED DESCRIPTION OF THE INVENTION The inventors have made an extensive study to develop a novel Ni-based alloy which is excellent not only in anti-corrosion properties but also in workability, and as a result, they have found that the addition of Ta (tantalum) is essential to obtain the desired properties. Thus, the Ni-based alloy in accordance with the present invention is principally characterized in that it contains 15 to 35 weight % of Cr (chromium); 17 to 23 weight % of Mo (molybdenum), wherein the sum of Cr plus Mo is no greater than 43 weight %; 1.3 to 3,4 weight % of Ta (tantalum); with the optional elements listed in claim 1; balance Ni (nickel) and unavoidable impurities. The Ni-based alloy may preferably further include one or more of 0.0001 to 0.1 weight % of N (nitrogen), 0.0001 to 3 weight % of Mn (manganese), 0.0001 to 0.3 weight % of Si (silicon), 0.001 to 0.1 weight % of C (carbon), 0.01 to 6 weight % of Fe (iron), 0.001 to 0.1 weight % of Zr (zirconium), 0.001 to 0.01 weight % of Ca (calcium), 0.1 to 1 weight % of Nb (niobium), 0.1 to 4 weight % of W (tungsten), 0.1 to 4 weight % of Cu (copper), 0.05 to 0.8 weight % of Ti (titanium), 0.01 to 0.8 weight % of Al (aluminum), 0.1 to 5 weight % of Co (cobalt), 0.1 to 0.5 weight % of V (vanadium), 0.1 to 2 weight % of Hf (hafnium), 0.01 to 3 weight % of Re (rhenium), 0.01 to 1 weight % of Os (osmium), 0.01 to 1 weight % of Pt (platinum), 0.01 to 1 weight % of Ru (ruthenium), 0.01 to 1 weight % of Pd (palladium), 0.01 to 0.1 weight % of La (lanthanum), 0.01 to 0.1 weight % of Ce (cerium), and 0.01 to 0.1 weight % of Y (yttrium). The reasons for the restrictions on the numerical ranges for respective essential or optional ingredients in the above Ni-based alloy will be now explained in detail. Chromium : The Cr component is dissolved in the matrix to form a solid solution therewith, and improves anti-corrosion properties such as anti-pitting corrosion property and anti-crevice corrosion property in the environment containing chlorine ions. However, if the Cr content is less than 15 weight %, such advantages cannot be expected. On the other hand, if the Cr content exceeds 35 weight %, the other useful ingredients such as Mo and Ta are prevented from dissolving into the matrix, and the aforesaid corrosion properties are deteriorated due to less presence of such effective ingredients. Therefore, the Cr content is determined so as to range between 15 to 35 weight %. The most preferable range of the Cr content is from 17 to 22 weight % for the same reasons. Molybdenum : The Mo component is also dissolved in the matrix to form a solid solution therewith, and improves anti-corrosion properties such as anti-pitting corrosion property and anti-crevice corrosion property in the environment containing chlorine ions. Therefore, the Mo content is determined so as to range between 17 to 23 weight %. Furthermore, if Mo and Cr are added in such an amount that their total amount exceeds 43 weight %, the hot-working workability is drastically deteriorated. Therefore, the sum of Mo plus Cr is determined so as to be no greater than 43 weight %. Tantalum : The Ta component is dissolved in the matrix to form a solid solution therewith, and stabilizes and facilitates passivation film. Specifically, it is known that the passivation film which Ni-Cr-Mo alloy forms includes NiO-Cr 2 O 3 , and that minute Cr 2 O 3 dominantly contributes as a protective film. When Ta is added, Ta 2 O 5 which is stronger than Cr 2 O 3 is formed in the passivation film to further stabilize the film, so that the anti-corrosion properties, such as anti-pitting corrosion property or anti-crevice corrosion property in an environment containing chlorine ions, can be further enhanced. Therefore, the Ta content is determined so as to range between 1.3 to 3.4 weight %. Furthermore, if Ta and Mo are added in such an amount that their total amount ranges from 13 to 26 weight %, the anti-corrosion properties can be further enhanced. Nitrogen : The N component is dissolved in the matrix to form a solid solution therewith, and stabilizes the FCC phase and prevents the formation of deleterious TCP phases, so that the hot working workability is improved. Specifically, when Cr, Mo and Ta, which are added to improve the anti-corrosion properties, exceed certain amounts, TCP phases are unduly formed to lower the hot working workability. However, with the addition of N, the latent period for the formation of the TCP phases is prolonged to maintain the formed amount of the TCP phases in a permissible amount, and contributes to the stabilization of the FCC phases, so that the hot working workability is prevented from deteriorating. In the foregoing, if the N content is less than 0.0001 weight %, such advantages cannot be obtained. On the other hand, if the N content exceeds 0.1 weight %, nitrides such as Cr 2 N phase are separated in the matrix to deteriorate the hot working workability. Therefore, the N content is determined so as to range between 0 to 0.1 and preferably 0.0001 to 0.1 weight %. The most preferable range of the N content is from 0.001 to 0.05 weight % for the same reasons. Silicon : The Si, optionally as a deoxidizer, reduces oxides and prevents intercrystalline cracking. Therefore, Si reduces the intercrystalline cracking during the hot working operation to improve the hot working workability. However, if the Si content is less than 0.0001 weight %, such advantages cannot be obtained. On the other hand, if the Si content exceeds 0.3 weight %, TCP phases are formed in an undue amount to deteriorate the hot working workability. Therefore, the Si content is determined so as to range between 0 to 0.3 wt.% and preferably 0.0001 to 0.3 weight %. The most preferable range of the Si content is from 0.0001 to 0.1 weight % for the same reasons. Manganese : Although not as effective as N, the Mn component stabilizes FCC phase in the matrix to improve the anti-corrosion properties. However, if the Mn content is less than 0.0001 weight %, such advantages cannot be obtained. On the other hand, if the Mn content exceeds 3 weight %, TCP phases are unduly formed to lower the hot working workability. Therefore, the Mn content is determined so as to range between 0 and 3 wt.% and preferably 0.0001 to 3 weight %. The most preferable range of the Mn content is from 0.0001 to 1 weight % for the same reasons. Carbon : The C component is dissolved into the matrix to form a solid solution therewith, and stabilizes the FCC phase therein and inhibits the formation of deleterious TCP phases to improve the hot working workability. However, if the C content is less than 0.001 weight %, such advantages cannot be obtained. On the other hand, if the C content exceeds 0.1 weight %, the formation of carbides is unduly increased to lower the hot working workability. Therefore, the C content is determined so as to range between 0 and 0.1 wt.% and preferably 0.001 to 0.1 weight %. The most preferable range of the C content is from 0.001 to 0.05 weight % for the same reasons. Iron : As is the case with N, the Fe component is dissolved into the FCC phase in the matrix to form a substitution solid solution therewith, and stabilizes the FCC phase. Therefore, it improves the hot working workability. However, if the Fe content is less than 0.01 weight %, such advantages cannot be obtained. On the other hand, if the Fe content exceeds 6 weight %, it reduces the anti-corrosion properties in an environment containing chlorine ions, in particular anti-pitting corrosion property and anti-crevice corrosion property. Therefore, the Fe content is determined so as to range between 0 to 6 wt.% and preferably 0.01 to 6 weight %. The most preferable range of the Fe content is from 0.05 to 4 weight % for the same reasons. Boron, Zirconium, Calcium : These ingredients enhance the hot working workability. However, if each of B, Zr and Ca is added in a respective amount of less than 0.001 weight %, such advantages cannot be obtained. On the other hand, if the amounts of B, Zr and Ca exceed 0.1 weight %, 0.1 weight % and 0.01 weight %, respectively, the hot working workability is then deteriorated. Therefore, the B, Zr and Ca contents are determined so as to range from 0 to 0.1 wt.% for B, from 0 to 0.1 wt.% for Zr and from 0 to 0.01 wt.% for Ca and preferably from 0.001 to 0.1 weight %, 0.001 to 0.1 weight % and 0.001 to 0.01 weight %, respectively. For the same reasons, the most preferable range is 0.002 to 0.01 weight % for B; 0.002 to 0.01 weight % for Zr; and 0.002 to 0.009 weight % for Ca. Niobium, Tungsten, Copper : These ingredients enhance the anti-corrosion properties in an environment containing chlorine ions. However, if each amount of Nb, W and Cu is less than 0.1 weight %, such advantages cannot be obtained. On the other hand, if the amounts of Nb, W and Cu exceed 1 weight %, 4 weight % and 4 weight %, respectively, the formation of the TCP phases is unduly increased so that the hot working workability is deteriorated. Therefore, the Nb, W and Cu contents are determined so as to range from 0-1 wt.%, 0-4 wt.% and 0-4 wt.% and preferably 0.1 to 1 weight %, 0.1 to 4 weight %, and 0.1 to 4 weight %, respectively. For the same reasons, the most preferable range is 0.15 to 0.5 weight % for Nb; 0.2 to 2 weight % for W; and 0.2 to 2 weight % for Cu. Titanium, Aluminum, Cobalt, Vanadium : These ingredients enhance the hot working workability, in particular ductility and strength. However, if the Ti, Al, Co and V ingredients are less than 0.05 weight %, 0.01 weight %, 0.1 weight % and 0.1 weight %, respectively, such advantages cannot be obtained. On the other hand, if the Ti, Al, Co and V ingredients exceed 0.8 weight %, 0.8 weight %, 0.5 weight %, and 0.5 weight %, respectively, ductility is lowered. Therefore, the Ti, Al, Co and V contents are determined if they are to be included at all so as to preferably range from 0.05 to 0.8 weight %, 0.01 to 0.8 weight %, 0.1 to 5 weight %, and 0.1 to 0.5 weight %, respectively. For the same reasons, the most preferable range is 0.08 to 0.4 weight % for Ti; 0.05 to 0.4 weight % for Al; 0.2 to 2 weight % for Co; and 0.2 to 0.4 weight % for V. Hafnium, Rhenium : These ingredients enhance the anti-corrosion properties in an environment containing chlorine ions, such as anti-pitting corrosion property and anti-crevice corrosion property, and improves hot working workability. These ingredients are added especially when required to enhance these properties. However, if the Hf and Re ingredients are less than 0.1 weight % and 0.01 weight %, respectively, such advantages cannot be obtained. On the other hand, if the Hf and Re ingredients exceed 2 weight % and 3 weight %, respectively, the deleterious TCP phases are formed unduly so that the anti-corrosion properties and the hot working workability are extremely lowered. Therefore, the Hf and Re contents are determined if they are to be included at all so as to preferably range from 0.1 to 2 weight % and 0.01 to 3 weight %, respectively. Due to the same reasons, the most preferable range is 0.2 to 1 weight % for Hf and 0.02 to 1 weight % for Re. Osmium, Platinum, Ruthenium, Palladium : These ingredients are optionally added, and when at least one from these components is added, the hot working workability of the alloy is improved. However, if each of the Os, Pt, Ru and Pd ingredients is added in a respective amount of less than 0.01 weight %, such advantages cannot be obtained. On the other hand, if each of these ingredients is added in an amount exceeding 1 weight %, the deleterious TCP phases are formed unduly so that the hot working workability is extremely lowered. Therefore, these ingredients are determined so as to preferably range from 0.01 to 1 weight %. For the same reasons, the most preferable range is 0.02 to 0.5 weight % for each of these ingredients. Lanthanum, Cerium, Yttrium : These ingredients are optionally added, and improve anti-corrosion properties in the environment containing chlorine ions. However, if each of the La, Ce and Y ingredients is added only in an amount of less than 0.01 weight %, such advantages cannot be obtained. On the other hand, if each of these ingredients is added in an amount exceeding 0.1 weight %, the deleterious TCP phases are formed unduly so that the hot working workability is extremely lowered. Therefore, each of these ingredients is determined so as to preferably range from 0.01 to 0.1 weight %. For the same reasons, the most preferable range is 0.02 to 0.08 weight % for La, 0.01 to 0.08 weight % for Ce and Y. Impurities : It is inevitable that S (sulfur), Sn (tin), Zn (zinc) and Pb (lead) are included as impurities in the material to be melt. However, if the amounts of these impurities are no greater than 0.01 weight %, respectively, the alloy characteristics are not deteriorated at all. In the aforesaid Ni-based alloy, Mg (magnesium) may be further included in an amount of 0.0001 to 0.3 weight % since Mg reduces intercrystalline cracking during hot working to improve the hot working workability. However, if the Mg content is less than 0.0001 weight %, such advantages cannot be obtained. On the other hand, if the Mg content exceeds 0.3 weight %, segregation occurs at grain boundaries, so that the hot working workability is lowered. Therefore, the Mg content is determined so as to range from 0.0001 to 0.3 weight %. The more preferable range for the Mg content is from 0.001 to 0.1 weight %. The Ni-based alloys in accordance with the present invention are excellent in both hot working workability and anti-corrosion properties. Accordingly, they can be used to manufacture devices of complicated shapes used in severe environments containing chlorine ions, such as bleaching devices in the paper and pulp industry, pipings for hydrogen gas for halogenation, or HCl recovery columns. As described above, the Ni-based alloys of the invention are the most useful when used in an environment containing chlorine ions. However, the application is not limited to such use, and they may be used in environments which contain acids such as hydrochloric acid, hydrofluoric acid, oxalic acid, phosphoric acid, or nitric acid; alkalis such as sodium hydroxide; and sea water which is neutral. Furthermore, the inventors have found that among the Ni-based alloys of the invention, some specific alloys are very resistant to a variety of sulfuric acid corrosion. More specifically, the inventors have classified the sulfuric acid environment into the following three categories: (a) a sulfuric acid environment of 60% and 80% sulfuric acid at 120°C; (b) a sulfuric acid environment containing chlorine ions which has reducing acidic characteristic; (c) a sulfuric acid environment containing active carbon (i.e., unburned carbon), Fe 3+ or HNO 3 which is more corrosive with respect to oxidizing acidic characteristics. The inventors have made extensive study to develop Ni-based alloys which have excellent anti-corrosion properties in the aforesaid sulfuric acid environments. As a result, they have found a Ni-based alloy containing 17 to 22 weight % of Cr; 19 to 23 weight % of Mo, wherein the sum of Cr plus Mo is greater than 38 weight % and no greater than 43 wt%; 0.01 to 4.0 weight % of Fe; 1,3 to 3,4 weight % of Ta. Optionally, at least one selected from.the group consisting of 0.001 to 0.01 weight % of Zr and 0.001 to 0.01 weight % of B may be included. Furthermore, at least one of 0.1 to 0.5 weight % of Nb, 0.1 to 2.0 weight % of W, and 0.1 to 2.0 weight % of Cu may be added so as to satisfy that the total of 4Nb + W + Cu is no greater than 2.0 weight %. In the foregoing, the numerical ranges for respective ingredients have been determined due to the following reasons. Chromium, Molybdenum : As described before, the Cr and Mo components improve anti-corrosion properties, but the Cr component in particular improves the anti-corrosion property against oxidizing acids, whereas Mo enhances such properties against the non-oxidizing acids. Therefore, it is appreciated that the simultaneous addition of Cr and Mo with Ta makes the alloy to be substantially resistant in various sulfuric acidic environments. However, if the Cr content is less than 17 weight %, it is difficult to form a passivation film on the alloy surface minute enough to impart sufficient resistance to sulfuric acid. The preferred upper limit of 22 weight % is set simply because sufficient workability is expected within this range. Furthermore; if the Mo content is less than 19 weight %, sufficient anti-corrosive property against sulfuric acid cannot be obtained. On the other hand, if the Mo content exceeds 23 weight %, the resistance to the sulfuric acid including oxidizing acid is reduced. In the foregoing, Cr and Mo have properties opposite to each other. Therefore, it is important to balance the Cr and Mo contents with each other, and to determine the amount of Cr plus Mo so as to preferably range from 38 to 43 weight %. Otherwise, the anti-corrosion property with respect to sulfuric acid is deteriorated. Accordingly, the sum of Cr plus Mo is determined so as to be greater than 38 weight % and be no greater than 43 weight %. Tantalum : In order to ensure the well-balanced resistance to a variety of the sulfuric acidic environments, the Ta content is from 1.3 to 3.4 weight %. For the same reasons, the most preferable range is from 1.5 to 2.5 weight %. Iron : In order to improve the workability of plastic working, it is preferable that Fe be added in an amount of no less than 0.01 weight %. However, if the Fe content exceeds 4.0 weight %, the anti-corrosion property with respect to the sulfuric acid is deteriorated. Therefore, the Fe content in the embodiment of claim 14 has been set from 0.01 to 4.0 weight %. Boron, Zirconium : The B and Zr contents are determined so as to preferably range from 0.001 to 0.01 weight % due to the same reasons as mentibned above. Niobium, Tungsten, Copper : In order to ensure sufficient anti-corrosion properties with respect to the sulfuric acids as well as excellent workability, the Nb, W and Cu contents are given in the claims but are preferably determined so as to range from 0.1 to 0.5 weight %, 0.1 to 2.0 weight %, and 0.1 to 2.0 weight %, respectively. In addition, the sum of 4Nb + W + Cu should preferably be no greater than 2 weight % in order to ensure superior workability. The invention will be more detailedly explained by way of the following examples. Example 1 The raw materials were melted in a high-frequency melting furnace in an atmosphere which was set to that of a mixture of argon and nitrogen gases and the mixing ratio of N 2 as well as the pressure of the mixture were varied. The melt was cast into molds to provide ingots having a diameter of 60 mm and a length of 200 mm. The ingots thus obtained were melt again in an electroslag melting furnace to provide ingots having a diameter of 100 mm and compositions shown in Tables 1 to 13. The ingots were then subjected to homogenization treatment while keeping them at a prescribed temperature between 1150 to 1250°C for 10 hours, and parts of the ingots were cut as test pieces for high-temperature compression tests, while the remainder was subjected to hot forging and hot rolling at prescribed temperatures between 1000 to 1250°C to produce hot-rolled plates 5 mm thick. The rolled: plates thus obtained were subjected to solution heat treatment by keeping them at a prescribed temperature ranging from 1150 to 1250°C for 30 minutes, and were further subjected to cold rolling to provide cold-rolled plates 3 mm thick. Subsequently, the cold-rolled plates were further subjected to solution heat treatment by keeping them at a prescribed temperature ranging from 1150 to 1250°C for 30 minutes to provide Ni-based alloy plates 1 to 43 of the invention and comparative Ni-based alloy plates 1 to 14. Furthermore, conventional Ni-based alloy plates 1 to 4 were produced by "alloy 55C", "alloy 625", "alloy C-276" and "alloy C-22", respectively. With respect to the Ni-based alloy plates 1 to 43 of the invention, the comparative Ni-based alloy plates 1 to 14, and the conventional Ni-based alloy plates 1 to 4, the high-temperature compression test, the high-temperature tension test, and anti-pitting corrosion and anti-crevice corrosion tests in the environment containing chlorine ions were carried out. High-Temperature Compression Test : Cylindrical test pieces of 8 mm in diameter and 12 mm long were cut from the ingots by means of electrical discharging, and held at 1,100°C for 15 minutes. Then, the test pieces were compressed at a rate of strain of 1.0 mm/sec to a target distortion of 50 %, and the stresses when compressed at 10% distortion were measured to evaluate the hot working workability. The results are set forth in Tables 14 to 19. High-Temperature Tension Test : Test pieces for high-temperature tension test were obtained from the cold-rolled plates 3 mm thick, and after having been held at a high temperature of 800°C for 15 minutes, the test pieces were tensioned at 0.15 mm/min up to 0.2 % proof stress and at 1.50 mm/min after 0.2 % proof stress. Then, the elongation until breakage was performed to evaluate the workability in hot working. The results are shown in Tables 14 to 19. Anti-Pitting Corrosion Test in Environment Containing Chlorine Ions : Test pieces of 35 mm in both length and width were prepared from the cold-rolled plates 3 mm thick, and were subjected to wet grinding to smooth the surface up to #2400. Then, the test pieces were immersed in an aqueous solution of 150°C and pH of 2 and containing 4% of NaCl, 0.1% of Fe 2 (SO 4 ) 3 , 0.01 Mol of HCl, and 24300 ppm of Cl - for 24 hours, and then the presence of the pitting corrosion was examined microscopically at a magnification of 40. The results of the measurements are shown in Tables 14 to 19. Anti-Crevice Corrosion Test in Environment Containing Chlorine Ions : Test pieces of 35 mm in both length and width were prepared from the cold-rolled plates 3 mm thick, and were subjected to wet grinding to smooth the surface up to #2400. Then, in accordance with ASTM Practice G46-76B, test pieces each as shown in Figure 1 were prepared by securing a respective plate-like test piece 1 and a respective Teflon round rod 2 by a rubber cord 3 or the like, to provide test pieces for pitting corrosion. The test pieces were then immersed in a boiling aqueous solution containing 11.5% of H 2 SO 4 , 1.2% of HCl, 1% of FeCl 3 , 1% of CuCl 2 for 24 hours, and then the depth of corrosion was measured. The results of the measurements are also shown in Tables 14 to 19. As will be seen from the results shown in Tables 1 to 19, the Ni-based alloy plates 1-43 of the invention are superior in workability in hot working to the conventional Ni-based alloy plate 1, and superior in the anti-corrosion properties in an environment containing chlorine ions over the conventional Ni-based alloy plates 2, 3 and 4. Therefore, the Ni-based alloy plates 1 to 43 of the invention are superior in both the hot working workability and anti-corrosion properties when compared with the conventional Ni-based alloy plates. Furthermore, as seen with the comparative Ni-based alloy plates 1 to 14, if the composition falls outside the claimed ranges, at least one of the hot working workability and the anti-corrosion properties is inferior. Example 2 The same procedures as in Example 1 were repeated to produce ingots of 100 mm in diameter having compositions as shown in Tables 20 to 34, and to prepare Ni-based alloy plates 44 to 104 of the invention and comparative Ni-based alloy plates 15 to 27. Furthermore, the conventional Ni-based alloy plates 1 to 4 were again used and shown in Table 34. With respect to the Ni-based alloy plates 44 to 104 of the invention and the comparative Ni-based alloy plates 15 to 26, the high-temperature compression test, the high-temperature tension test, and anti-pitting corrosion and anti-crevice corrosion tests in the environment containing chlorine ions were carried out. The results are shown in Tables 35 to 40. As will be seen from Tables 35 to 40, the Ni-based alloy plates 44 to 104 of the invention are superior in workability in hot working to the conventional Ni-based alloy plate 1, and superior in the anti-corrosion properties in an environment containing chlorine ions over the conventional Ni-based alloy plates 2 to 4. Therefore, the Ni-based alloy plates 44 to 104 of the invention are superior in both the hot working workability and anti-corrosion properties when compared with the conventional Ni-based alloy plates. Furthermore, as seen with the comparative Ni-based alloy plates 15 to 27, if the composition falls outside the claimed ranges, at least one of the hot working workability and the anti-corrosion properties is inferior. Example 3 The raw materials were melted in a high-frequency melting furnace, and the melt was cast into ingots of 8.5 mm thick having compositions shown in Tables 41 to 44. The ingots thus obtained were heated to a temperature ranging from 1,000 to 1,230°C, and while maintaining them at this temperature, hot rolling operation was once carried out to reduce the thickness to 8 mm. Subsequently, by carrying out the hot rolling operation several times and reducing the thickness 1 mm for each operation, the thickness was reduced to 3 mm. Thus, Ni-based alloy plates 105 to 120 of the invention, comparative Ni-based alloy plates 28 to 43 and conventional Ni-based alloys 5 to 9, each of which has a thickness of 3 mm, were prepared. These Ni-based alloy plates were all examined as to the presence of cracks during the rolling operation, and the results of the examination are set forth in Tables 41 to 44. Furthermore, the aforesaid Ni-based alloys were cut into test pieces of 25 mm in length and 50 mm in breadth. Furthermore, 60% of H 2 SO 4 , 80 % of H 2 SO 4 , a solution in which 1 g of active carbon was suspended in 3 cc of 60% of H 2 SO 4 (hereinafter referred to as "60% H 2 SO 4 with active carbon"), a solution in which 1 g of active carbon was suspended in 3 cc of 80% of H 2 SO 4 (hereinafter referred to as "80% H 2 SO 4 with active carbon"), a solution in which 100 ppm of HCl was added to 60% of H 2 SO 4 (hereinafter referred to as "60% H 2 SO 4 + 100 ppm HCl"), a solution in which 10 ppm of HNO 3 wars added to 60% of H 2 SO 4 (hereinafter referred to as "60% H 2 SO 4 + 10 ppm HNO 3 "), and a solution in which 400 ppm of Fe 3+ was added as Fe 2 (SO 4 ) 3 to 60% of H 2 SO 4 (hereinafter referred to as "60% H 2 SO 4 + 400 ppm Fe 3+ ") were prepared. These sulfuric acid solutions were heated to 120°C, and the Ni-based alloys of the invention, the comparative Ni-based alloys and the prior art Ni-based alloys were immersed in these sulfuric acid solutions for 24 hours. Then, taking the alloys out, their weights were measured, and by dividing the reduced weight by the surface area, the rate of corrosion for one year was calculated. The results are set forth in Tables 45 to 48. As will be seen from Tables 41 to 48, the Ni-based alloy plates 105 to 120 of the invention are excellent in hot wdrking workability because no cracks ocurred during the hot rolling operations. In addition, the rates of corrosion against 60% of H 2 SO 4 , 80 % of H 2 SO 4 , 60% H 2 SO 4 with active carbon, 80% H 2 SO 4 with active carbon, 60% H 2 SO 4 + 100 ppm HCl, 60% H 2 SO 4 + 10 ppm HNO 3 , and 60% H 2 SO 4 + 400 ppm Fe 3+ , were all less than 1 mm/year. Thus, the Ni-based alloy plates 105 to 120 of the invention are excellent in resistance to various sulfuric acidic environments. In contrast, some of the comparative Ni-based alloy plates and the prior art Ni-based alloy plates exhibited rates of corrosion exceeding 1 mm/year, while others exhibited rates of corrosion of less than 1 mm/year, but cracked during hot rolling operation and were inferior in workability. Ni-based alloy plate of the present invention (unit: weight %) element 1 2 3 4 5 6 Cr 20.1 21.2 19.9 21.0 18.8 19.2 Mo 19.7 20.8 21.9 18.2 17.4 20.9 Ta 1.72 1.53 1.23 3.34 3.01 1.75 N 0.0006 0.0284 0.0342 0.0481 0.0083 0.0445 Si 0.0214 0.0325 0.0224 0.0432 0.0342 0.0016 Mn 0.0729 0.0816 0.4253 0.8425 0.1926 0.2856 C 0.0058 0.0088 0.0120 0.0109 0.0083 0.0125 Fe 0.05 1.01 3.84 0.11 0.51 0.88 B 0.003 - - 0.009 0.005 - Zr - 0.004 - 0.002 0.007 0.003 Ca - - 0.002 - 0.001 0.008 Nb - - - - - - W - - - - - - Cu - - - - - - Ti - - - - - - Al - - - - - - Co - - - - - - V - - - - - - Hf - - - - - - Re - - - - - - Os, Pt - - - - - - Pd, Ru - - - - - - La, Ce, Y - - - - - - Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 7 8 9 10 11 12 Cr 17.9 18.0 20.5 21.2 19.8 19.2 Mo 20.1 22.3 20.6 21.0 20.7 21.5 Ta 1.55 2.51 1.88 1.65 1.38 1.92 N 0.0342 0.0253 0.0009 0.0083 0.0127 0.0210 Si 0.0026 0.0098 0.0002 0.0981 0.0218 0.0113 Mn 0.0172 0.0036 0.0018 0.0173 0.0003 0.9856 C 0.0141 0.0075 0.0098 0.0105 0.0121 0.0029 Fe 0.01 1.24 1.05 2.13 1.18 1.79 B 0.002 - - 0.003 - - Zr - 0.003 - - 0.07 - Ca - - 0.007 0.002 - 0.06 Nb - - - - - - W - - - - - - Cu - - - - - - Ti - - - - - - Al - - - - - - Co - - - - - - V - - - - - - Hf - - - - - - Re - - - - - - Os, Pt - - - - - - Pd, Ru - - - - - - La, Ce, Y - - - - - - Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 13 14 15 16 Cr 20.6 21.0 20.0 24.8 Mo 22.1 21.3 19.7 17.9 Ta 2.08 2.21 2.03 2.05 N 0.0382 0.0415 0.0002 0.0412 Si 0.0714 0.0514 0.0873 0.0726 Mn 0.5216 0.4266 0.0025 2.9526 C 0.0014 0.0148 0.0083 0.0153 Fe - - - - B - 0.004 0.002 - Zr - - - 0.011 Ca - - - - Nb - - - - W - - - - Cu - - - - Ti - - - - Al - - - - Co - - - - V - - - - Hf - - - - Re - - - - Os, Pt - - - - Pd, Ru - - - - La, Ce, Y - - - - Ni+imp bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 17 18 19 20 21 Cr 19.2 17.2 18.8 21.7 22.5 Mo 19.1 18.3 18.2 18.1 17.8 Ta 1.91 2.49 2.11 2.91 30.7 N 0.0265 0.0422 0.0543 0.0186 0.0312 Si 0.0387 0.0116 0.0083 0.0062 0.0787 Mn 0.2283 0.0391 0.0598 0.7382 0.0084 C 0.0081 0.0115 0.0101 0.0073 0.0114 Fe 0.02 5.82 - - - B - - - - - Zr - - - - - Ca - - - - - Nb - - 0.14 0.92 - W - - - - 0.17 Cu - - - - - Ti - - - - - Al - - - - - Co - - - - - V - - - - - Hf - - - - - Re - - - - - Os, Pt - - - - - Pd, Ru - - - - - La, Ce, Y - - - - - Ni+imp bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 22 23 24 Cr 21.6 17.3 20.6 Mo 18.1 20.8 18.3 Ta 1.52 2.63 1.69 N 0.0008 0.0185 0.0352 Si 0.0935 0.0658 0.0328 Mn 0.5918 0.2913 0.0562 C 0.0093 0.0085 0.1183 Fe 0.02 5.82 0.25 B - - - Zr - - 0.091 Ca - - - Nb - - 0.38 W - - 2.29 Cu 0.12 3.94 - Ti - - - Al - - - Co - - - V - - - Hf - - - Re - - - Os, Pt - - - Pd, Ru - - - La, Ce, Y - - - Ni+imp bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 25 26 27 28 29 30 Cr 20.3 19.6 18.2 21.1 20.5 21.5 Mo 20.6 19.7 21.8 19.2 18.3 19.7 Ta 1.71 1.33 1.99 2.25 2.00 2.09 N 0.0522 0.0362 0.0048 0.0162 0.0315 0.0223 Si 0.0933 0.0526 0.0625 0.0328 0.0362 0.0413 Mn 0.4381 0.2795 0.0595 0.0287 0.1316 0.1425 C 0.0124 0.0078 1.0056 0.0038 0.0127 0.0062 Fe - - - - 0.04 - B - - - - - - Zr - - - - 0.043 - Ca - - - - - - Nb - - - - - - W - - - - - - Cu - - - - 0.52 - Ti 0.06 0.78 - - 0.09 - Al - - 0.02 0.77 0.24 - Co - - - - - 0.14 V - - - - - - Hf - - - - - - Re - - - - - - Os, Pt - - - - - - Pd, Ru - - - - - - La, Ce, Y - - - - - - Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 31 32 33 34 35 Cr 17.6 20.5 20.3 19.8 21.3 Mo 18.1 19.2 18.5 21.2 18.6 Ta 1.66 2.56 2.12 1.52 2.53 N 0.0245 0.0538 0.0391 0.0272 0.0353 Si 0.0386 0.0278 0.0096 0.0121 0.0235 Mn 0.8295 0.4365 0.0039 0.0021 0.0285 C 0.0078 0.0114 0.0125 0.0112 0.0087 Fe - - 1.25 - - B - - 0.009 - - Zr - - - - - Ca - - - - - Nb - - 0.14 - - W - - - - - Cu - - - - - Ti - - 0.34 - - Al - - - - - Co 4.83 - 2.03 - - V - 0.12 0.13 - - Hf - - - 0.15 1.93 Re - - - - - Os, Pt - - - - - Pd, Ru - - - - - La, Ce, Y - - - - - Ni+imp bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 36 37 38 Cr 20.3 21.6 20.3 Mo 19.9 18.6 19.2 Ta 2.25 2.81 1.98 N 0.0515 0.0622 0.0461 Si 0.0959 0.0287 0.0742 Mn 0.4956 0.3692 0.3815 C 0.0138 0.0129 0.0081 Fe - - - B - - - Zr - - - Ca - - - Nb - - - W - - - Cu - - - Ti - - - Al - - - Co - - - V - - - Hf - - - Re - - - Os, Pt Os:1.93 Pt:0.02 Pt:0.88 Pd, Ru - - - La, Ce, Y - - - Ni+imp bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 39 40 Cr 21.9 22.5 Mo 18.3 18.1 Ta 2.55 1.75 N 0.0344 0.0292 Si 0.0090 0.0950 Mn 0.0291 0.0004 C 0.0027 0.0085 Fe - - B - - Zr - - Ca - - Nb - - W - - Cu - - Ti - - Al - - Co - - V - - Hf - - Re - - Os, Pt - Os:0.57 Pd, Ru Pd:0.02 Pd:0.21 La, Ce, Y - - Ni+imp bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 41 42 43 Cr 20.6 21.7 17.3 Mo 20.0 20.1 17.1 Ta 2.11 2.06 2.15 N 0.0495 0.0511 0.0150 Si 0.0425 0.0516 0.0224 Mn 0.5256 0.5461 0.3825 C 0.0038 0.0126 0.0086 Fe - - 0.08 B - - - Zr - - 0.006 Ca - - - Nb - - - W - - 1.34 Cu - - - Ti - - - Al - - 0.04 Co - - 1.55 V - - - Hf - - 1.06 Re - - - Os, Pt - - - Pd, Ru - - - La, Ce, Y Ce:0.04 Y:0.06 - Ni+imp bal. bal. bal. (Note: imp represents unavoidable impurities) Comparative Ni-based alloy plates (unit: weight %) element 1 2 3 4 5 6 Cr 14.5* 35.4* 30.1 18.4 21.6 20.9 Mo 20.2 6.4 5.6* 24.3* 22.1 19.6 Cr+Mo 34.7 41.8 35.7 42.7 43.7* 40.5 Ta 3.26 6.97 2.96 1.28 2.25 0.98* N 0.0211 0.0405 0.0422 0.0365 0.0292 0.0191 Si 0.0932 0.0825 0.0516 0.0421 0.0386 0.0392 Mn 0.2457 0.1653 0.4281 0.3625 0.0292 0.0573 C 0.0114 0.0087 0.0092 0.0087 0.0071 0.0088 Fe 0.19 0.07 0.09 1.27 - 2.31 B 0.007 - - - - 0.008 Zr - 0.009 - - - - Ca - - 0.002 - - - Nb - - - - - - W - - - - - - Cu - - - - - - Ti - - - - - - Al - - - - - - Co - - - - - - V - - - - - - Hf - - - - - - Re - - - - - - Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities, and the values with an * are out of the range of the present invention.) Comparative Ni-based alloy plates (unit: weight %) element 7 8 9 10 11 12 Cr 19.3 20.1 20.3 21.5 19.1 19.4 Mo 15.7 22.7 19.8 21.2 20.8 21.0 Cr+Mo 34.9 42.9 40.1 42.7 39.9 40.4 Ta 8.33* 2.83 1.85 1.38 1.66 1.89 N 0.0275 -* 0.1156* 0.0651 0.0361 0.0351 Si 0.0275 0.0437 0.0420 0.3243* 0.0735 0.0551 Mn 0.0239 0.0128 0.5956 0.9212 3.4526* 0.1583 C 0.0136 0.0256 0.0467 0.0097 0.0028 0.3215* Fe - - 0.81 - - - B - - 0.006 - - - Zr - - - - - - Ca - - - - - - Nb - - - - - - W - - - - - - Cu - - - - - - Ti - - - - - - Al - - - - - - Co - - - - - - V - - - - - - Hf - - - - - - Re - - - - - - Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities, and the values with an * are out of the range of the present invention.) Comparative Ni-based alloy plates Conventional Ni-based alloy plates element 13 14 1 2 3 4 Cr 18.5 19.3 30.1 21.5 16.1 21.5 Mo 21.2 19.6 20.3 9.0 16.2 13.2 Cr+Mo 39.7 38.9 50.7 30.5 32.3 34.7 Ta 2.01 1.88 - - - - N 0.0426 0.0305 - - - - Si 0.0438 0.0485 - - - - Mn 0.2895 0.4255 - - - - C 0.0166 0.0028 - - - - Fe 6.32* 0.18 - 2.5 5.2 - B - 0.12* - - - - Zr - - - - - - Ca - - - - - - Nb - - - 3.7 - - W - - - - 3.2 3.2 Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities, and the values with an * are out of the range of the present invention.) type hot working workability anti-corrosion property deformation resistance under 1100°C (kg/mm 2 ) elongation up to rupture under 800°C (%) pitting depth of crevice corrosion (mm) Ni-based alloy plate of the present invention 1 18.7 52.6 none 0.08 2 18.9 53.7 none 0.09 3 19.7 56.4 none 0.13 4 17.9 51.3 none 0.15 5 18.6 53.8 none 0.17 6 18.5 50.6 none 0.15 7 18.9 50.9 none 0.14 8 19.4 45.2 none 0.14 9 18.3 51.2 none 0.15 10 18.7 50.3 none 0.16 11 18.6 49.2 none 0.14 12 18.9 48.1 none 0.13 13 19.2 49.5 none 0.13 14 18.3 51.3 none 0.14 15 18.7 53.1 none 0.18 type hot working workability anti-corrosion property deformation resistance under 1100°C (kg/mm 2 ) elongation up to rupture under 800°C (%) pitting depth of crevice corrosion (mm) Ni-based alloy plate of the present invention 16 17.5 58.7 none 0.13 17 18.4 50.2 none 0.19 type hot working workability anti-corrosion property deformation resistance under 1100°C (kg/mm 2 ) elongation up to rupture under 800°C (%) pitting depth of crevice corrosion (mm) Ni-based alloy plate of the present invention 18 17.8 55.4 none 0.16 19 17.9 53.9 none 0.18 20 18.1 57.3 none 0.08 21 18.3 58.3 none 0.07 22 17.5 57.8 none 0.11 23 18.4 56.7 none 0.12 24 17.9 47.3 none 0.08 25 18.8 61.2 none 0.18 26 18.9 60.3 none 0.19 27 18.3 62.2 none 0.15 28 18.5 50.1 none 0.14 29 17.8 56.2 none 0.18 30 18.9 51.3 none 0.19 type hot working workability anti-corrosion property deformation resistance under 1100°C (kg/mm 2 ) elongation up to rupture under 800°C (%) pitting depth of crevice corrosion (mm) Ni-based alloy plate of the present invention 31 17.3 49.8 none 0.11 32 18.9 50.7 none 0.12 33 19.1 51.3 none 0.14 34 19.5 48.2 none 0.15 35 17.9 56.2 none 0.11 36 18.5 50.5 none 0.09 37 18.8 51.2 none 0.07 38 18.5 50.8 none 0.11 39 17.9 54.3 none 0.11 type hot working workability anti-corrosion property deformation resistance under 1100°C (kg/mm 2 ) elongation up to rupture under 800°C (%) pitting depth of crevice corrosion (mm) Ni-based alloy plate of the present invention 40 19.3 50.5 none 0.15 41 18.9 49.5 none 0.11 42 19.2 49.2 none 0.13 43 16.8 62.9 none 0.14 Comparative Ni-based alloy plates 1 15.2 67.3 present 0.26 2 20.1 45.6 none 0.21 3 15.4 60.3 present 0.36 4 21.6 39.8 none 0.15 5 22.7 38.5 none 0.13 6 18.9 45.6 present 0.38 7 21.9 39.6 none 0.18 8 20.5 38.5 none 0.11 type hot working workability anti-corrosion property deformation resistance under 1100°C (kg/mm 2 ) elongation up to rupture under 800°C (%) pitting depth of crevice corrosion (mm) Comparative Ni-based alloy plate 9 22.9 20.5 none 0.18 10 19.2 38.3 none 0.18 11 18.7 43.8 present 0.21 12 21.8 37.6 none 0.18 13 17.7 55.7 present 0.22 14 19.3 38.8 none 0.17 Conventional Ni-based alloy plate 1 29.8 8 none 0.02 2 16.4 62 present 1.18 3 19.1 65 present 0.88 4 8.5 60 present 0.71 Ni-based alloy plate of the present invention (unit: weight %) element 44 45 46 47 Cr 17.1 21.8 19.8 21.6 Mo 21.6 20.1 20.0 18.1 Ta 1.94 1.83 2.20 2.22 N 0.0224 0.0326 0.0349 0.0132 Mg 0.0028 0.0226 0.0274 0.0039 Si 0.0427 0.0522 0.0586 0.0422 Mn 0.0143 0.2855 0.3050 0.3218 C 0.0139 0.0120 0.0044 0.0098 Fe - - - - B - - - - Zr - - - - Ca - - - - Nb - - - - W - - - - Cu - - - - Hf - - - - Ti - - - - Al - - - - Co - - - - V - - - - Ni+imp bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 48 49 50 51 52 Cr 18.4 19.3 20.2 21.4 20.7 Mo 22.2 21.4 20.1 19.6 18.4 Ta 2.05 2.08 2.19 2.38 1.97 N 0.0018 0.0492 0.0315 0.0121 0.0092 Mg 0.0098 0.0123 0.0015 0.0294 0.0103 Si 0.0381 0.0349 0.0203 0.0057 0.0956 Mn 0.0854 0.0458 0.0488 0.1219 0.1668 C 0.0039 0.0053 0.0187 0.0115 0.0082 Fe - - - - - B - - - - - Zr - - - - - Ca - - - - - Nb - - - - - W - - - - - Cu - - - - - Hf - - - - - Ti - - - - - Al - - - - - Co - - - - - V - - - - - Ni+imp bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 53 54 55 Cr 17.9 18.4 15.2 Mo 21.0 19.7 20.4 Ta 2.34 2.85 3.82 N 0.0086 0.0053 0.0244 Mg 0.0164 0.0243 0.0114 Si 0.0984 0.0055 0.0427 Mn 0.4943 0.2734 0.3725 C 0.0128 0.0193 0.0083 Fe - - - B - - - Zr - - - Ca - - - Nb - - - W - - - Cu - - - Hf - - - Ti - - - Al - - - Co - - - V - - - Ni+imp bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 56 57 58 59 Cr 19.2 17.6 21.1 20.8 Mo 20.8 21.2 19.5 19.4 Ta 1.93 1.55 2.12 2.03 N 0.0005 0.0462 0.0338 0.0485 Mg 0.0118 0.0072 0.0006 0.2954 Si 0.0743 0.0376 0.0155 0.0091 Mn 0.0135 0.0372 0.0927 0.1387 C 0.0105 0.0167 0.0044 0.0063 Fe - - - - B - - - - Zr - - - - Ca - - - - Nb - - - - W - - - - Cu - - - - Hf - - - - Ti - - - - Al - - - - Co - - - - V - - - - Ni+imp bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 60 61 62 63 64 65 Cr 20.4 19.9 18.3 19.6 19.6 19.7 Mo 19.1 20.8 21.2 21.4 18.5 20.1 Ta 1.80 1.84 2.09 2.20 1.87 2.02 N 0.0230 0.0054 0.0119 0.0251 0.0285 0.0309 Mg 0.0132 0.0105 0.0239 0.0281 0.0103 0.0029 Si 0.2934 0.0562 0.0442 0.0276 0.0832 0.0726 Mn 0.2895 2.9862 0.1382 0.0835 0.4255 0.3463 C 0.0129 0.0147 0.0988 0.0049 0.0187 0.0105 Fe - - - - 5.85 - B - - - - - 0.0974 Zr - - - - - - Ca - - - - - - Nb - - - - - - W - - - - - - Cu - - - - - - Hf - - - - - - Ti - - - - - - Al - - - - - - Co - - - - - - V - - - - - - Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 66 67 68 69 70 71 Cr 19.8 19.7 19.8 20.2 19.9 20.1 Mo 19.2 20.5 20.3 19.7 20.4 19.2 Ta 1.84 1.76 2.04 1.93 1.82 2.25 N 0.0178 0.0315 0.0051 0.0188 0.0276 0.0242 Mg 0.0045 0.0073 0.0185 0.0270 0.0139 0.0273 Si 0.0358 0.0379 0.0147 0.0088 0.0093 0.0147 Mn 0.0295 0.0133 0.0058 0.0295 0.1395 0.3526 C 0.0129 0.0182 0.0027 0.0091 0.0105 0.0134 Fe - - 0.02 0.58 0.84 - B - - 0.0017 - - 0.0275 Zr - 0.0982 - - 0.0085 - Ca 0.0094 - - 0.0015 - 0.0032 Nb - - - - - - W - - - - - - Cu - - - - - - Hf - - - - - - Ti - - - - - - Al - - - - - - Co - - - - - - V - - - - - - Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 72 73 74 75 76 77 Cr 20.4 19.6 19.8 20.0 20.2 20.3 Mo 20.3 19.4 20.2 20.3 19.7 20.8 Ta 2.09 2.11 1.89 1.73 1.85 2.29 N 0.0276 0.0130 0.0240 0.0284 0.0225 0.0134 Mg 0.0198 0.0115 0.0218 0.0244 0.0175 0.0127 Si 0.0285 0.0635 0.0678 0.0556 0.0398 0.0275 Mn 0.4566 0.0288 0.0125 0.0259 0.0105 0.0224 C 0.0116 0.0198 0.0155 0.0120 0.0177 0.0181 Fe - - 1.52 2.24 1.54 - B 0.0342 - 0.0074 - 0.0135 0.0042 Zr 0.0127 0.0088 - 0.0143 0.0192 0.0083 Ca - 0.0045 0.0027 0.0035 - 0.0055 Nb - - - - - - W - - - - - - Cu - - - - - - Hf - - - - - - Ti - - - - - - Al - - - - - - Co - - - - - - V - - - - - - Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 78 79 80 81 Cr 19.3 19.2 21.0 20.5 Mo 20.7 17.2 18.4 20.8 Ta 1.75 1.83 2.26 1.89 N 0.0172 0.0155 0.0154 0.0133 Mg 0.0152 0.0246 0.0138 0.0201 Si 0.0752 0.0621 0.0054 0.0213 Mn 0.3564 0.0293 0.0838 0.0732 C 0.0119 0.0077 0.0166 0.0180 Fe 0.01 - - 0.08 B 0.0015 - - - Zr 0.0013 - - - Ca 0.0014 - - - Nb - 0.92 - 0.13 W - - - 0.14 Cu - - - - Hf - - 1.96 - Ti - - - - Al - - - - Co - - - - V - - - - Ni+imp bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 82 83 84 85 86 87 Cr 20.8 19.9 19.6 19.7 20.1 20.2 Mo 19.2 20.3 19.5 20.9 19.7 19.8 Ta 1.94 1.99 1.87 2.15 2.27 2.09 N 0.0208 0.0421 0.0270 0.0332 0.0309 0.0394 Mg 0.0155 0.0287 0.0098 0.0139 0.0162 0.0130 Si 0.0356 0.0511 0.0435 0.0048 0.0019 0.0209 Mn 0.1518 0.2360 0.1829 0.0327 0.0225 0.0138 C 0.0077 0.0098 0.0085 0.0191 0.0148 0.0092 Fe - - - - - - B 0.0045 - - - - - Zr - - 0.0038 - - - Ca - 0.0022 - - - - Nb - - 0.19 - - - W 0.12 - - - - - Cu 0.11 0.28 - - - - Hf - 0.35 0.14 - - - Ti - - - 0.77 - - Al - - - - 0.78 - Co - - - - - 4.95 V - - - - - - Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 88 89 90 91 92 93 Cr 19.7 20.8 20.2 20.5 20.3 19.2 Mo 20.5 20.4 20.5 20.8 20.6 19.5 Ta 2.10 1.85 1.93 1.79 2.06 1.80 N 0.0135 0.0170 0.0024 0.0054 0.0088 0.0125 Mg 0.0165 0.0129 0.0223 0.0256 0.0145 0.0236 Si 0.0156 0.0024 0.0557 0.0438 0.0296 0.0210 Mn 0.0927 0.4238 0.4325 0.3863 0.0284 0.0363 C 0.0083 0.0125 0.0115 0.0104 0.0080 0.0106 Fe - 0.92 - - - 2.25 B - - 0.0041 - - - Zr - - - - 0.0033 - Ca - - - 0.0027 - - Nb - 0.25 - - - 0.19 W - - 0.45 - - - Cu - - - 0.33 - - Hf - - - - 0.28 - Ti - 0.06 - - 0.09 - Al - 0.02 0.04 - - - Co - - 0.13 0.29 - - V 0.48 - - 0.12 0.18 - Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 94 95 96 97 98 99 Cr 17.9 18.2 18.4 19.6 19.5 18.7 Mo 18.6 18.9 19.1 19.3 18.4 18.2 Ta 1.81 1.34 2.03 2.22 2.56 2.18 N 0.0018 0.0078 0.0173 0.0215 0.0089 0.0110 Mg 0.0015 0.0132 0.0161 0.0213 0.0085 0.0155 Si 0.0832 0.0775 0.0655 0.0542 0.0331 0.0448 Mn 0.1283 0.0835 0.0721 0.0085 0.0134 0.0155 C 0.0133 0.0029 0.0018 0.0052 0.0043 0.0085 Fe 0.85 0.62 1.15 1.28 1.33 1.49 B - - - - - - Zr - - - - - - Ca - - - - - - Nb - - - - - - W 1.23 - - - - - Cu - 1.55 - - - - Hf - - 0.82 - - - Ti - - - 0.14 - - Al - - - - 0.18 - Co - - - - - 0.56 V - - - - - - Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Ni-based alloy plate of the present invention (unit: weight %) element 100 101 102 103 104 Cr 18.9 17.7 18.3 18.5 19.2 Mo 19.5 20.2 19.1 20.3 20.0 Ta 1.43 1.55 1.78 1.95 1.46 N 0.0028 0.0133 0.0115 0.0092 0.0359 Mg 0.0225 0.0181 0.0235 0.0080 0.0119 Si 0.0820 0.0735 0.0098 0.0332 0.0090 Mn 0.1443 0.0826 0.2234 0.0186 0.0563 C 0.0131 0.0029 0.0086 0.0112 0.0042 Fe 1.25 2.56 2.48 - 0.02 B - - - - 0.002 Zr - - - - 0.002 Ca - - - - 0.001 Nb - - 0.26 - 0.11 W - - 0.43 - 0.14 Cu - - 0.55 0.88 0.11 Hf - - 0.26 0.31 0.12 Ti - 0.13 - - 0.07 Al - 0.06 - - 0.02 Co - 0.9 - - 0.13 V 0.18 0.21 - 0.12 0.11 Ni+imp bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities.) Comparative Ni-based alloy plates (unit: weight %) element 15 16 17 18 19 20 Cr 14.5* 35.6* 29.8 17.4 20.1 19.8 Mo 20.1 6.3 5.4* 25.6* 19.7 15.4 Ta 3.30 6.82 3.03 1.31 0.91* 8.52* N 0.0255 0.0356 0.0428 0.0283 0.0193 0.0354 Mg 0.0785 0.0246 0.0180 0.0058 0.0173 0.0059 Si 0.0804 0.0529 0.0618 0.0742 0.0121 0.0388 Mn 0.2881 0.1825 0.3935 0.4351 0.0565 0.0745 C 0.0105 0.0098 0.0125 0.0143 0.0044 0.0075 Fe - - - - - - B - - - - - - Zr - - - - - - Ca - - - - - - Nb - - - - - - W - - - - - - Cu - - - - - - Hf - - - - - - Ti - - - - - - Al - - - - - - Co - - - - - - V - - - - - - Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities, and the values with an * are out of the range of the present invention.) Comparative Ni-based alloy plates (unit: weight %) element 21 22 23 24 25 Cr 20.4 20.7 20.5 21.5 19.2 Mo 22.3 19.6 21.1 21.2 20.7 Ta 2.88 1.95 2.59 1.38 1.73 N -* 0.12* 0.0557 0.0651 0.0365 Mg 0.0225 0.0170 0.33* 0.0295 0.0145 Si 0.0225 0.0595 0.0146 0.32* 0.0733 Mn 0.0384 0.2765 0.4829 0.8356 3.25* C 0.0144 0.0049 0.0159 0.0079 0.0028 Fe - - - - - B - - - - - Zr - - - - - Ca - - - - - Nb - - - - - W - - - - - Cu - - - - - Hf - - - - - Ti - - - - - Al - - - - - Co - - - - - V - - - - - Ni+imp bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities, and the values with an * are out of the range of the present invention.) Comparative Ni-based alloy plates Conventional Ni-based alloy plates element 26 27 1 2 3 4 Cr 19.8 19.3 30.1 21.5 16.1 21.5 Mo 20.8 19.6 20.3 9.0 16.2 13.2 Ta 1.88 1.87 - - - - N 0.0352 0.0305 - - - - Mg 0.0145 0.0177 - - - - Si 0.0829 0.0485 - - - - Mn 0.1411 0.4255 - - - - C 0.1105* 0.0028 - - - - Fe - 6.33* - 2.5 5.2 - B - - - - - - Zr - - - - - - Ca - - - - - - Nb - - - 3.7 - - W - - - - 3.2 3.2 Ni+imp bal. bal. bal. bal. bal. bal. (Note: "imp" represents unavoidable impurities, and the values with an * are out of the range of the present invention.) type hot working workability anti-corrosion property deformation resistance under 1100°C (kg/mm 2 ) elongation up to rupture under 800°C (%) pitting depth of crevice corrosion (mm) Ni-based alloy plate of the present invention 44 18.6 54.8 none 0.08 45 18.4 51.6 none 0.07 46 19.2 48.6 none 0.09 47 18.3 49.2 none 0.11 48 18.8 48.2 none 0.14 49 18.9 52.5 none 0.12 50 19.1 51.1 none 0.14 51 18.8 50.2 none 0.10 52 19.2 51.3 none 0.11 53 19.8 50.9 none 0.09 54 19.4 49.6 none 0.10 55 18.8 52.6 none 0.17 type hot working workability anti-corrosion property deformation resistance under 1100°C (kg/mm 2 ) elongation up to rupture under 800°C (%) pitting depth of crevice corrosion (mm) Ni-based alloy plate of the present invention 56 19.3 51.2 none 0.18 57 19.0 50.0 none 0.16 58 18.5 49.7 none 0.17 59 19.4 52.3 none 0.17 60 18.6 49.1 none 0.18 61 18.1 48.7 none 0.18 62 18.6 44.2 none 0.19 63 18.5 52.6 none 0.13 64 18.5 52.1 none 0.16 65 18.4 50.6 none 0.15 66 19.2 50.9 none 0.17 67 18.6 49.8 none 0.15 type hot working workability anti-corrosion property deformation resistance under 1100°C (kg/mm 2 ) elongation up to rupture under 800°C (%) pitting depth of crevice corrosion (mm) Ni-based alloy plate of the present invention 68 19.9 52.9 none 0.18 69 18.1 51.1 none 0.13 70 18.4 52.5 none 0.18 71 18.4 51.3 none 0.17 72 18.7 50.4 none 0.16 73 19.4 52.3 none 0.17 74 18.5 51.8 none 0.16 75 18.0 49.5 none 0.16 76 18.4 49.6 none 0.17 77 18.9 48.8 none 0.18 78 18.8 52.5 none 0.19 79 18.2 48.8 none 0.18 80 19.4 49.2 none 0.16 81 19.0 48.8 none 0.16 type hot working workability anti-corrosion property deformation resistance under 1100°C (kg/mm 2 ) elongation up to rupture under 800°C (%) pitting depth of crevice corrosion (mm) Ni-based alloy plate of the present invention 82 19.6 47.2 none 0.18 83 19.4 48.1 none 0.14 84 19.2 48.2 none 0.16 85 19.8 49.5 none 0.17 86 19.5 50.1 none 0.18 87 19.5 44.5 none 0.15 88 19.0 52.1 none 0.14 89 18.9 50.3 none 0.16 90 19.6 48.8 none 0.15 91 19.8 46.5 none 0.14 92 19.7 48.2 none 0.16 93 18.8 44.6 none 0.15 94 18.5 50.2 none 0.14 95 18.6 50.1 none 0.14 96 19.1 49.3 none 0.15 97 19.3 48.1 none 0.13 type hot working workability anti-corrosion property deformation resistance under 1100°C (kg/mm 2 ) elongation up to rupture under 800°C (%) pitting depth of crevice corrosion (mm) Ni-based alloy plate of the present invention 98 19.5 51.6 none 0.16 99 19.6 52.1 none 0.17 100 19.3 51.0 none 0.15 101 19.2 49.8 none 0.15 102 18.1 50.6 none 0.14 103 19.9 51.3 none 0.14 104 18.7 50.9 none 0.12 Comparative Ni-based alloy plate 15 15.2 67.3 present 0.26 16 20.2 45.8 none 0.21 17 15.4 60.3 present 0.37 18 broken during rolling - - - 19 18.9 45.6 present 0.38 20 21.9 38.8 none 0.13 21 20.5 38.4 none 0.11 22 22.8 20.2 present 0.18 type hot working workability anti-corrosion property deformation resistance under 1100°C (kg/mm 2 ) elongation up to rupture under 800°C (%) pitting depth of crevice corrosion (mm) Comparative Ni-based alloy plate 23 broken during rolling - - - 24 19.2 38.3 none 0.18 25 18.7 43.8 present 0.25 26 21.8 37.4 none 0.18 27 18.6 38.9 present 0.21 Conventional Ni-based alloy plate 1 29.8 8 none 0.02 2 16.4 62 present 1.18 3 19.1 65 present 0.88 4 18.5 60 present 0.21

Claims: A nickel-based alloy consisting of: 15 to 35 weight % of chromium; 17 to 23 weight % of molybdenum; wherein the sum of chromium plus molybdenum is no greater than 43 weight %; 1,3 to 3,4 weight % of tantalum; optionally, no greater than 0.1 weight % of nitrogen; no greater than 0.3 weight % of magnesium, no greater than 3 weight % of manganese, no greater than 0.3 weight % of silicon, no greater than 0.1 weight % of carbon, no greater than 6 weight % of iron, no greater than 0,1 weight % of boron, no greater than 0.1 weight % of zirconium, no greater than 0.01 weight % of calcium, no greater than 1 weight % of niobium, no greater than 4 weight % of tungsten, no greater than 4 weight % of copper, no greater than 0.8 weight % of titanium, no greater than 0.8 weight % of aluminum, no greater than 5 weight % of cobalt, no greater than 0.5 weight % of vanadium, no greater than 2 weight % of hafnium, no greater than 3 weight % of rhenium, no greater than 1 weight % of osmium, no greater than 1 weight % of platinum, no greater than 1 weight % of ruthenium, no greater than 1 weight % of palladium, no greater than 0.1 weight % of lanthanum, no greater than 0.1 weight % of cerium, no greater than 0.1 weight % of yttrium; and balance nickel and unavoidable impurities. A nickel-based alloy according to claim 1, wherein nitrogen is contained in an amount of no less than 0.0001 weight %. A nickel-based alloy according to any of the preceding claims, wherein magnesium is contained in an amount of no less than 0.0001 weight %. A nickel-based alloy according to any of the preceding claims, wherein iron is contained in an amount of no less than 0.001 weight %. A nickel-based alloy according to any of the preceding claims wherein Si is contained in an amount of no less than 0.0001 weight %. A nickel-based alloy according to any of the preceding claims wherein Mn is contained in an amount of no less than 0.0001 weight %. A nickel-based alloy according to any of the preceding claims wherein C is contained in an amount of no less than 0.001 weight %. A nickel-based alloy according to any of the preceding claims, wherein at least one of boron, zirconium and calcium is contained in a respective amount of no less than 0.001 weight %. A nickel-based alloy according to any of the preceding claims, wherein at least one of niobium, tungsten and copper is contained in a respective amount of no less than 0.1 weight %. A nickel-based alloy according to any of the preceding claims, wherein at least one of no less than 0.05 weight % of titanium, no less than 0.01 weight % of aluminum, no less than 0.1 -weight % of cobalt, and no less than 0.1 weight % of vanadium is contained. A nickel-based alloy according to any of the preceding claims, wherein at least one of no less than 0.1 weight % of hafnium and no less than 0.01 weight % of rhenium is contained. A nickel-based alloy according to any of the preceding claims, wherein at least one of osmium, platinum, ruthenium and palladium is contained in a respective amount of no less than 0.01 weight %. A nickel-based alloy according to any of the preceding claims, wherein at least one of lanthanum, cerium, and yttrium is contained in a respective amount of no less than 0.01 weight %. A nickel-based alloy according to claim 1, including: 17 to 22 weight % of chromium; 19 to 23 weight % of molybdenum; wherein the sum of chromium plus molybdenum is greater than 38 weight % and no greater than 43 weight %; 1,3 to 3,4 weight % of tantalum; 0.01 to 4.0 weight % of iron; and optionally, no greater than 0.01 weight % of zirconium, no greater than 0.01 weight % of boron, no greater than 0.5 weight % of niobium, no greater than 2 weight % of tungsten and no greater than 2 weight % of copper, wherein [4 x niobium + tungsten + copper] ≤ 2 weight %. A nickel-based alloy according to claim 14, wherein at least one of zirconium and boron is contained in a respective amount of no less than 0.001 weight %. A nickel-based alloy according to claim 14 or claim 15, wherein at least one of niobium, tungsten and copper is contained in a respective amount of no less than 0.1 weight %. The use of a nickel-based alloy as defined in any one of claims 1 to 16 in an environment containing chlorine ions. The use of a nickel-based alloy as defined in an one of claims 1 to 16 in exhaust gas desulphurizers, chemical plants, electroplating devices, boilers, food processing devices, medical equipment, structural members for semiconductor devices or cutter blades and manual tools which are exposed to sea water.

Inventors: KITAMURA HIDEO, SUGAHARA KATSUO, TAKAHASHI TSUTOMU, TAKIZAWA YOSHIO, TOYOKURA KOJI, WAKITA SABURO, KITAMURA, HIDEO, SUGAHARA, KATSUO, TAKAHASHI, TSUTOMU, TAKIZAWA, YOSHIO, TOYOKURA, KOJI, WAKITA, SABURO, KITAMURA, HIDEO, C/O CHUO-KENKYUSHO, SUGAHARA, KATSUO, C/O CHUO-KENKYUSHO, TAKAHASHI, TSUTOMU, C/O IWAKI-SEISAKUJYO, TAKIZAWA, YOSHIO, C/O CHUO-KENKYUSHO, TOYOKURA, KOJI, C/O CHUO-KENKYUSHO, WAKITA, SABURO, C/O CHUO-KENKYUSHO
Applicants: MITSUBISHI MATERIALS CORP, MITSUBISHI MATERIALS CORPORATION
Application year: 1994
Main classification: C22C19
IPC codes: C22C19